A distributed packet concatenation scheme for sensor and ad hoc networks

Along with the growing popularity of sensor and ad hoc networks, various kinds of services are expected to be supported. In wireless ad hoc networks, there are increasing demands for Web traffic, voice over IP and streaming video from and to the Internet via the access points. In sensor networks, event-driven or periodically monitoring services are common. However, various lengths of packets are used in different services. Short packets have relatively large overhead at the MAC (medium access control) and physical layers and hence can significantly decrease the network throughput. In this paper, we analyze the performance of a distributed adaptive packet concatenation (APC) scheme which is proposed to improve the network throughput. The APC scheme works at the interface queue of the data link layer. It adaptively concatenates several short packets which are destined to the same next hop into a long packet for MAC layer's transmission according to the congestion status as well as the observed channel status. The theoretical analysis is conducted in both single hop networks and multihop networks, and the result shows that the APC scheme can increase the throughput by up to 4 to 16 times.